Determinants question bank (Mathematics)

If $\begin{bmatrix} 2 & 1 & -1 \\ -1 & 2 & 1 \\ 1 & -1 & 2 \end{bmatrix} \begin{bmatrix} a \\ b \\ c \end{bmatrix} = \begin{bmatrix} 4 \\ 0 \\ -2 \end{bmatrix}$ then the distance of point $P(a, b, c)$ from the plane $2x + y + 2z = 10$ is

The lines $x+2 a y+a=0, x+3 b y+b=0, x+4 c y+c=0$ are concurrent then $a, \mathrm{~b}, \mathrm{c}$ are in